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Technology
Landscape
Creation technology
Graphics
Aircraft models
Cockpit
Landscape representation
Graphical effects
Aerodynamics
General equations
Flight characteristics setting
Aerodynamics
 Realistic flight dynamics are a characteristic of the Flanker line of simulators. Lock On naturally continues this tradition.
- In the dynamic model, non-simplified motion equations are used. Such equations do not overlook inertial characteristics of the plane.
- In the model of the engine, real thrust - fuel consumption dependence on flight speed and altitude is considered. This provides real flight characteristics (acceleration, rate of climb, ceiling, maximum and minimum speed, flight range and time).
- Non-linear corrections at high angles of attack are taken into account. This enables the ability to model flight at supercritical angles of attack and also stall modes and spins.
- For more complicated modes, animation elements are used, for example, for the so called aerobatic "cobra" for Su-27, Su-33 and Mig-29.
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General equations
Center of mass motion in wind axes is described by the following equations used at flight characteristics calculation (disregarding sliding)
where
| H | - is flight altitude; |
| V | - is aircraft speed; |
| dV/dt | - is acceleration; |
| θ | - is flight path angle; |
| ψ | - is heading; |
| P | - is engine thrust; |
| Qsec | - is second fuel consumption; |
| G | - is aircraft weight; |
| φ | - is angle between thrust vector and axe x; |
| γ | - is angle of roll; |
| q | - is dynamic pressure; |
| Cx | - is drag coefficient; |
| Cy | - normal force coefficient. |
Sliding is described by the following equation:
When moving on the ground friction force is added: Ffriction = kfr * G * (1 - Ny).
When calculating Mach number and dynamic pressure the table of standard atmosphere is used.
At present in FM the following dependences are accepted for aerodynamics and engine characteristics:
Cy = Cyalfa(M) * α + Cyflaps * k(q) + nonlinear correction(α); Cy ≤ Cymax(M);
Cz = Czbeta(M)* β ;
Cx = Cx0(M) + Cxflaps + Cxpld(M) + Bpol(M) * Cy ** 2 + Dpol(M) * Cy ** 4 - Czbeta * β ** 2;
P(M,H,Dr) = F1(M)*F2(H)*F3(Dr);
Qsec = Ce * P / 3600
where:
| M | - is Mach number; |
| α | - is angle of attack; |
| β | - is slide angle; |
| Dr | - is engine operating mode. |
Dependences Cyalfa(M), Cymax(M), Czbeta(M), Cx0(M), Cxpld(M), Bpol(M), Dpol(M), F1(M), F2(H), F3(Dr) are set by the tables with linear interpolation.
To get real aerodynamics characteristics of aircraft and engine flight characteristics is rather difficult due to secrecy of such information. When there is not enough information on aerodynamics characteristics and engine flight characteristics we have to correct various table dependences to agree then with known flight characteristics (accelerations, turns, climb, flight range, etc).
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Flight characteristics setting
Below you can find comparative data on flight characteristics as calculated in Lock On. This data was taken from official open sources.
 Dependence of rate of turn in relation to velocity. A steady turn at an altitude of 200 m above sea level for F-15C aircraft. Data from technical resources and those calculated in Lock On are compared.
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This diagram illustrates the F-15C acceleration characteristics in regards to Mach over time at an altitude of 3,050 m with maximum engine thrust. Here you can find the data from official sources and those calculated in Lock On program. You can see just how close they are.
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Permissible Flight Data area is an envelope showing permissible values of Altitude/Mach number variables for the F-15C.. Here you can find the data from official sources and those calculated in Lock On.
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Comparison of acceleration characteristics for the F-15C and Su-27.
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